Grinding wheel dressing tool



June 1, 1948. L Y 2,442,fl-53 GRINDING WHEEL DRESSING TOOL Filed June 28, 1945 I 4 Sheets-Sheet 1 June 1, 1948. EY I 2,442,453

GRINDING WHEEL DRESSING TOOL Filed June 28, 1945 4 Sheets-Sheet 2 R Mm June 1, 1948. F. M. BLEY 2,442,453

GRINDING WHEEL DRESSING TOOL Filed June 28, 1945 4 Shets-Sheet 3 0/ 4 -36 34% A 35 35 J 27a June I, 1948. F. M. BLEY GRINDING WHEEL DRESSING TOOL 4' Sheets-Sheet 4 Filed June 28, 1945 jnvenfon fil mm farm I 0 44 Patented June I, 1948 UNITED STATES PATENT OFFICE GRINDING WHEEL DRESSING TOOL Fred M. Bley, Glenview, 111.

Application June 28, 1945, Serial No. 602,027

11 Claims. 1

This invention relates to tools for dressing grinding wheels, and has to do with a tool specially suited for dressing grinding wheels the operative surfaces of which have profiles which comprise either fiat surfaces or curved surfaces, or a combination of the two.

Tools for dressing grinding wheels having either flat surfaces or curved surfaces, or both, are known and extensively used, Such tools, in general, comprise a member having a cutting point of diamond or other suitable material highly resistant to abrasion, and means for imparting to the cutting point, in contact with the rotating grinding wheel, proper movements to dress the wheel to the desired profile. All of such tools, to my knowledge, are of rather complicated construction and operation, expensive, difficult to adjust and lacking in precision, particularly with respect to dressing arcuate surfaces and fiat surfaces tangent to arcuate surfaces.

My invention is directed to the provision of a tool for dressing grinding wheels, which is of comparatively simple and inexpensive construction, may be accurately adjusted with expedition and facility, and is particularly suited to precision work, especially in dressing grinding wheels having profiles involving arcuate surfaces and flat surfaces tangent to arcuate surfaces. More specifically, I provide a shaft rotatable about a fixed axis and a carriage turnable with the shaft about such axis and having a rectilinear movement transversely of the shaft, the carriage being provided with a tool arm rigid therewith having a provision for mounting a tool with its cutting point in a plane radial to the shaft. By swinging the shaft through an arc of proper radius, with the carriage in centered position relative to the shaft, an arcuate surface, either concaved or convexed, of the grinding wheel may be accurately formed to the desired radius, and by moving the carriage transversely of the shaft, with the latter turned through the proper angle from its normal or zero position, a flat surface of the grinding wheel may be accurately formed with assurance that it will be tangent to and merge smoothly into the arcuate surface, whereby precision in the dressing of such a Wheel is assured. The carriage is restrained against turning movement relative to the shaft, so that in order to dress a fiat surface all that is required is to set the shaft at the proper angle and then move the carriage in proper direction transversely of the shaft, which is conducive to ease and accuracy of adjustment and precision in the dressing operation. In order further to facilitate the detal description.

In the drawings:

Figure 1 is a plan view of a tool embodying my invention;

Figure 2 is an outer end view of the tool of Figure 1;

Figure 3 is a sectional View taken substantially on line 3- -3 of Figure 1, with the gauge member mounted in the tool arm for determining the position of the cutting point of the tool carried by the arm, certain parts being shown in elevation;

Figure 4 is a sectional view taken substantially on the line 4-4 of Figure 3, on an enlarged scale;

Figure 5 is a fragmentary sectional View taken substantially on line "5-5 of Figure 3, certain parts being shown in elevation;

Figure 6 is a fragmentary sectional view taken substantially on line 6-6 of Figure 2, certain parts being shown in elevation, on an enlarged scale;

Figure 7 is a fragmentary sectional View taken substantially on line 1-1 of Figure 2, certain parts being shown in elevation, on an enlarged scale;

Figure 8 is a diagrammatic'view showing the manner in which the tool of m'yinvention is used for dressing a grinding wheel having a profile comprising flat side surfaces tangent to a central surface of convexed arcuate form, the grinding wheel being shown fragmentarily;

Figure 9 is a diagrammatic view showing the views of grinding wheels of different profilesmy in-- which have been dressed by the tool of vention.

I have illustrated my invention, by way ofex ample, as embodied in a tool-intended for use with a magnetic chuck. The tool comprises .aframe l5 of cast iron or other suitablemagnetic, material, of substantially L shape in side View;

having a base l5 and upright support ll, the base being provided with suitably disposed pads or bosses for cooperation with the magnetic chuck. Support I? is thickened at its central area to provide a hub l8 suitably bored for reception of opposed bearing collars i9 and fitting snugly therein and secured in position by set screws 2 i and 22,.respectively.

A shaft 23, tapered outward of the upright support I! for a considerable portion of its length, extends through hub 18 and is mounted for rocking or oscillatory movement in relatively narrow Y inwardly extending flanges i941 and 20a of the bearing collars l9 and 20, respectively. The flanges 19a and 20a are formed accurately to. the taper of shaft 23 and support the latter in hub IS in accurate centered relation thereto. Itis 4 nut 38 is screwed tight-1y on the outer end of portion 21a of stud 21 into contact with the nut 36 and, in cooperation therewith, guards against the latter nut being turned outward along the portion 21a of stud 21. The bearing structure 3! takes both axial and radial thrusts, and assures ease in turning or swinging the lever 29 in either direction for turning of the shaft 23 in desired directions. It will be clear that the shaft 23 is effectively restrained against endwise movement relative to support i1, and is mounted to rotate about a fixed axis a-a.

Stud 2'! is provided with a flat 40 which is engaged by a flat ended set screw 4! threaded in hub 28 of lever 29, to assure that this lever will be mounted on stud 21 in predetermined anguquite diincult to machine a tapered bearing surface of substantial length to fit a tapered shaft to equal extent accurately and so as to assure that the shaft will be maintained on a fixed axis of rotation in all angular positions thereof, while also preventing any objectionable tilting or looseness of the shaft. By providing the bearing collars i9 and 20 with th flanges 19a and 20a, respectively, in restricted bearing contact with shaft 23, I avoid the difficulties referred to. since the relatively narrow bearing surfaces of the flanges Na and 20a can readily-be machined accurately to correspond to the taper of shaft 23. That assures that the shaft 23 is accurately centered in the hub l8 and will turn about a fixed axis in all angular positions thereof, while eliminating possibility of objectionable tilting or looseness of this shaft, which is important in a tool intended for precision work, such as the tool of my invention.

A mounting block 25, of dovetail section transversely and of rectangular form at its inner and outer faces, is fixed to the inner end of shaft 23, conveniently by being formed integral therewith, in centered relationthereto. This block 25 is provided at its inner face with a central inwardly extending interiorly threaded eye 26 fixed thereto, conveniently formed integral therewith, for a purpose which will be explained presently. The shaft 23 is provided, at the outer end of its tapered body portion, with a reduced stud 21 which extends through hub 28 of an operating arm 29, and through a thrust ring 30 seating at its radially outer portion against the outer end of hub [8 of support IT. Hub 28 of lever 29 is recessed from its inner face for reception of a ball-bearing structure 3! comprising an outer race 32 seating against the wall at the outer end of recess 33, an inner race 34 extending a slight distance inward beyond hub 28 and seating against the outer face of ring 30. and the intervening bearing balls 35, the race 32 fitting tightly about stud 21 and the race 34 fitting snugly but not tightly within the recess33, and also fitting snugly but not tightly about the stud 21, The outer end portion 21a of stud 2'! is threaded for reception of a nut 36 screwing thereon and seating against the outer end of hub 28, whereby the shaft 23, including stud 21 thereof, may be drawn into position seating snugly in the flanges l9a and 29a of the bearing collars l9 and 2!], respectively, and lever 29 is held in position on stud 21, with the inner race 34 of the ball-bearing assembly 3| seating firmly against the outer face of thrust ring 90, with the areas of the lever extending radially outward from recess 33 spaced a slight distance from the outer face of the corresponding area of the thrust ring 30. A can lar relation thereto. The support I! is formed concentrically with shaft 23 for the major portion of its periphery, and is provided on its edge with a scale 42 graduated in degrees and, if desired, in minutes, in opposite direction from a central zero mark coinciding with the vertical axial plane of shaft 23. A Vernier index member 43 is set into and suitably secured to the upper end of lever 29 and extends therefrom inward over the scale 42, this member 43 bearing on its upper face a scale 44 also graduated in degrees and, if desired, in minutes, at opposite sides of the zero lmark located on a radius of shaft 23 and on the lengthwise axis of lever 29. The lever 29 is provided, at its lower end, with a suitably formed outwardly projecting handle 45 to facilitate turning of the lever in desired direction and, a short distance above this handle, with a boss 46 suitably bored and tapped for reception of a locking screw 41 having a flat inner end engageable with the outer face of support I! for locking lever 29 in angular adjustment about the axis a-a of shaft 23, thereby also looking the shaft 23 in angular adjustment. The scale 42 and the vernier index member 43 cooperate to indicate the adjustment of lever 29 and shaft 23, as will be understood. In Figure 1 the zero mark of scale 44 is in register with the zero mark of scale 42, at which time the lever 29 is in its normal vertical position and the shaft 23 is in its normal position, which may be referred to as its zero position. The support I! is provided with an arcuate boss 50 concentric with stud 27 and disposed in major portion therebelow, and with an arcuate slot 5i formed in boss 58 likewise concentric with stud 21, the end portions of boss 59 and of slot 5| extending upward a material distance above axis a--a and the midlength of the boss and the slot being in the vertical plane of that axis. It will be seen that the slot 5| has an extent materially greater than for a reason which will be explained later. The slot 5| receives two hollow pins 52 corresponding in exterior diameter to the width of slot 5|, each having at its inner end a head 53 providing a flange seating against the inner face of boss 59. Each of the pins 52 is suitably bored and tapped from its outer end for reception of a reduced screw stud 54' of a cylindrical stop member or post 55 seating at its inner end against the outer end or face of boss 50, post 55 being provided in its outer end with a diametrical slot or kerf 56 for reception of the blade of a screw driver or other suitable tool for screwing stud 54 tightly into pin 52, and thereby clamping post 55 to support I! in any desired position along the slot 5!, The posts 55 are disposed at opposite sides of the operating lever 29 and provide means for limiting,

to desired extent, swinging movement of that lever in either direction.

The flat 48 of stud 2'! of shaft 23 is so disposed that the lengthwise axis of block 25 is in horizontal position, perpendicular to a plane passing through the zero mark or scale 42 and through axis a-a, when lever 29 is in its zero position with the zero mark of cale 44 in register with the zero mark of scale 42. A substantially cubiform carriage 58 is provided in its outer face with a lengthwise dovetail channel 58 which receives block 25, with a gib 68 disposed between the upper edge of block 25 and the upper wall of channel 59, this gib being held in position by socketed-head set screws 8| threading into carriage 58 adjacent the ends thereof and assuring a snug fit of the carriage 58 on block 25. The carriage 58 is thus slidably mounted on block 25 for lengthwise movement in either direction thereon, and has rectilinear movement transversely of shaft 23 while being restrained against turning movement relative thereto. Carriage 58 is further provided with a lengthwise groove 62 of substantially U shape in cross section, extending inward from groove 59 and closed at its ends by bosses 83 and 64. Groove '52 accommodates eye 28, and also accommodates a screw shaft 85 threading through eye 28. Shaft 85 is provided at one end with a reduced bearing stud 88 which fits snugly through the corresponding bore in boss 63, this stud 68 being provided at its outer end portion with a fiat 8'! which is engaged by the fiat inner end of a socketed-head set screw 68 threaded through a stop collar 89 mounted on stud 88 in contact with the outer face of boss 53. Boss 88 is provided with a bore coaxial with the bore of boss 63 but equal in diameter to shaft 65, which is provided at its other end with an untreacled portion 85a providing a bearing stud which seats in boss 68, shaft 65 being further provided with an integral collar l seating against the outer end of boss 88 and, outward beyond collar '18, with a squared stud II. It will be seen that the shaft 85 may be inserted endwise through boss 64 and threaded through eye 25 until stud 85 is seated in boss 53 and the shoulder of the shaft at the inner end of this stud is in contact with the inner face of boss 63, after which stop collar 88 may be secured on stud 68, shaft 85 being then restrained against endwise movement in either direction. The squared stud II is adapted to be received in a corresponding socket in a socket element I2 of a crank 13 provided with a suitable handle '14. By rotating the shaft 55 in proper direction, by means of the crank 53, carriage 58 may be moved in either direction along the block 25. The carriage 58 is provided, on its upper face, with a scale I6 graduated from opposite sides of a central zero mark in inches and fractions thereof, for indicating the extent of movement of carriage 58 in either direction from its normal central or zero position. An index pointer 3?, having its lower portion set in and fixed to block 25 at the outer face thereof, extends inward over scale i5 and cooperates therewith in an obvious manner. Adjacent scale it, the carriage 58 is provided with a lengthwise vertical gauging surface i8 and, contiguous thereto, a lengthwise horizontal gauging surface '19, the purpose of which will be described later. The carriage 58 is also provided, at its midlength, with a vertical slot 88 the outer end portion of which opens, at its upper end, into groove 59, the inner portion of this slot being flared upward as shown. A latch lever 8| is pivoted in slot 88, on a pin 82 secured in carriage 58, this lever being of a width, for the major portion of its length, to fit snugly in slot so as to be restrained by the walls thereof against movement lengthwise of pin 82. The lever 8| is provided, at its outer end, with a detent 83 of reduced width havin an upwardly extending and upwardly tapering tip element 84 adapted to engage snugly in a corresponding notch formed in the lower edge portion of block 25 at the midlength thereof. Lever 8| is urged in latching direction by a compression spring 81 seating at one end against the upper end of a bore 88 in carriage 58 opening at its lower end into slot 88, the lower end of spring 81 seating on the upper face of lever 8| about a centering pin 88 secured in the lever. The inner end portion of lever 8! is of approximately semi-cylindrical shape and is knurled, at 92, to provide a good grip for manipulating this lever. It will be seen that the lever 8|, in conjunction with detent 83 and tip element 84 and the compression spring 87, provides latch means for locking carriage 58 in accurately centered position to the block 25. In order to move the carriage 58 lengthwise along block 25, the inner end of lever 8| is raised, thus disengaging detent 83 from block 25 and enabling movement of carriage 58 lengthwise of the block. After the carriage has been moved a short distance in either direction from its normal center position, the lever 8| may be released and detent 84 thereof is then held in contact with the lower edge of block 25, along which it slides in the movement of the carriage. Upon return of the carriage to centered position, the detent 88 automatically enters the notch 85 of block 25, again locking the carriage thereto in centered position. In certain cases it may be desirable to have the carriage continue its travel beyond its central or zero position. To that end, the carriage is provided with a suitably disposed lengthwise bore 88a for reception of a, holding pin 88b. By raising the lever 8| to its dotted line position indicated in Figure 3, and inserting pin 88!) into position extending across slot 80, lever 8| is retained in its inoperative position, permitting continued travel of carriage 58 beyond its central position.

The underface of carriage 58 is flat or planar and seats accurately against the upper face of a boss or pad 93 at the outer end of a tool arm 84, conveniently formed of cast iron, suitably secured, as by means of screws 95, to carriage 58 and rigid therewith. Arm 94 is thickened at its inner portion to provide a mounting boss 86 pro vided with two cylindrical openings 81 and 98 extending therethrough with their axes in the plane of the lengthwise axis of arm 94, which latter axis is disposed in a plane radial to axis a-a of shaft 23. When the operating lever 29 is in its normal or zero position, with base 56 of frame I5 in horizontal position, the openings 91 and 88 are disposed in vertical position with their axes intersecting the axis aa of shaft 28, as will be clear from Figures 1 and 3. The opening 91 has associated therewith a socketed-head set screw 89 for adjustably securing therein a sleeve I88 in which is adjustably secured, by a set screw "II, a mounting member I82 having mounted therein, in a known manner, a cutting point I03 of a material highly resistant to abrasion, preferably a diamond. The opening 98 is adapted for reception of shank I8 3 of a gauge I85 adjustably secured by a set screw 98d and having, at the upper end of shank I84, a head I88 which extends a. consderable distance to one side of shank I04 and the underface of which is p rpendicular thereto and is provided with a thin layer or coating of a hard alloy, such as stellite, I01. The upper face of boss 95 is accurately machined so as to be fiat or planar and parallel with the axis a-a of shaft 23, providing a gauging surface I08 which, in cooperation with the underface of head I00, provides means for accurately adjusting the distance from surface I08 to the tip of the cutting point, as will be explained presently. The sleeve I is provided with a lengthwise fiat I00a engaged by the fiat end of set screw 99, which facilitates centering of the diamond point I53 accurately on the axis of opening 91 and assures that sleeve I00 is secured firmly in position. It will be understood that suitable oil holes (not shown) may be provided for lubricating the various bearings and bearing surfaces, and preferably a sealing washer IIO, of felt or other suitable material, is provided about the inner end of shaft 23 at the outer face of block 25, hub I8 of support II being suitably recessed for reception of the sealing washer or ring I I0.

In Figure 8 I have illustrated diagrammatically the use of the tool of my invention for dressing a grinding wheel I I2 having a profile comprising a central convexed area H3 curved on a regular are extending an equal distance to each side of the central vertical plane b-b of wheel H2, and two fiat side surfaces H4 and H5 each disposed at an angle to and merging into the curved central area or surface H3. The wheel H2 is suitably mounted and rotated about an axis perpendicular to the axisw-a of shaft 23, as is known. In setting up the dressing tool preliminary to the dressing operation, the gauge I04 is first adjusted so that surface I01 thereof is accurately spaced the proper distance away from gauge surface I08 of arm 94, this distance bein accurately measured by a micrometer or other suitable instrument. In order to dress a convexed arcuate surface, the distance between the surfaces I01 and I 63 should be less than the distance from surface I08 to axis a--a of shaft 23 by an amount equal to the radius of the desired arc. The sleeve I00 is then adjusted until the tip of the diamond point I03 contacts surface I0'I of the gauge, and is then secured firmly in-position, after which the gauge is removed. After that has been done, particularly in the case of Work requiring extreme accuracy, the setting of the tool is checked by gauges, in cooperation with the Vertical and horizontal surfaces I8 and I9, respectively, of carriage 58, with the latter locked in centered position, for testing the accuracy of the setting with respect to the arcuate surface H3, with lever 29 in its zero position. In checking the setting for each of the flat surfaces H4 and II 5, the lever 29 is turned through the proper angle at one side or the other of the axis a-a of shaft 23, as indicated on the scale 42, and is locked in such position by the locking screw 41, the carriage 58 remaining locked to block 25 in centered relation thereto during the checking operation, it being understood that lever 29 also is locked in its centered or zero position during the operation of checking the setting of the tool with respect to the arcuate surface II3. Assuming the setting of the tool to be correct,.the lever 29 is moved from its zero position over the scale 42 in one direction a distance equal to one-half of the length of the arc of surface H3, and is then looked in that position by the locking screw 41. The post 55, at the opposite isde of the lower portion of lever 29, is then brought into contact with the lever and secured tightly in such position. The lever 29 is then moved in theopposlte direction from its zero position a distance equal to one-half of the length of the desired arc, as indicated by the scale 42, is locked in such position, and the other post is moved into contact with the other side of the lower portion of the lever and secured firmly in position, as before. It will be seen that the two posts 55, thus positioned, constitute stops which limit swinging movement of the lever 29, and therefore limit movement of the diamond point I 03 about the axis a-a of shaft 23 to the length of the desired arc. After the setting of the tool has been tested and the proper adjustment has been made, as above, the dressing tool is positioned so as to bring the diamond point I 03 into cutting engagement with the grinding wheel II2, which is then rotated at appropriate speed. By swinging the lever 29 through an arc, as permitted by the posts or stops 55, with the carriage 58 remaining locked to block 25 in its centered position, the diamond point I03 of the cutting tool is moved about the axis a--a of shaft 23 through an arc of the same length as the desired surface H3 and dresses the central area of the wheel II2 accurately to the desired curvature. In order to dress the flat side surfaces H4 and H5, the dressing tool is withdrawn slightly from the wheel H2, sufiiciently to provide clearance for the diamond point I03, and lever 29 is swung first to one side and then to the opposite side of its zero position, the posts 55 having first been released and moved into positions to clear the lever, through an angle corresponding to the angle of inclination of the flat sides H4 and H5, and the posts 55 are secured in proper positions to limit the swinging movement of the lever 29 in either direction to that angle. Assuming that it is desired to dress first the surface II 4, the lever 29 is turned in clockwise direction, as viewed in Figure 2, until it contacts the left hand post 55, and is locked in that position by means of the locking screw 41. The carriage 58 is then released from block 25, by raising the inner end of latch lever 8|, and is moved along block 25 toward the left, or downward. as viewed in Fig ure 1, by rotating shaft in proper direction, a distance equal to that required for dressing surface II I, as indicated on the scale I6. After the carriage 58 has been moved a short distance in that direction, the lever 8i may be released and thereafter the detent 84 bears upon and slides along the lower edge of block 25. The dressing tool is then positioned so that the diamond point I03 will be brought into cutting engagement with the wheel II2, which is rotated as before, and by turning shaft 55 in proper direction the carriage 58 is moved along block 25 toward its central or zero position. During such travel of the carriage the diamond point I03 dresses the surface H4 to the desired angle and, since the carriage 58 turns about the same axis as the diamond point I03-the axis aa of shaft 23the surface H4 is tangent to and merges smoothly into the arcuate surface H3. In order to dress the surface H5, the lever 29 is swung into position in contact with the other post 55 and locked in that position, with the dressing tool remaining in operative relation to the wheel II2. In that connection, it should be noted that the carriage 58 is returned to centered position in the operation of dressing surface H4, in which position it is automatically locked by the latch lever BI and associated parts. In order to dress the surface II5, carriage 58 is unlocked from block 25 and, by rotating shaft 65 in proper direction, is moved from its centered or zero position upward, as viewed in Figure 1, and toward the right, the diamond point dressing surface H accurately to the desired angle during such travel of the carriage and this surface, when thus dressed, being tangent to and merging smoothly into the arcuate surface I 13. While the described procedure is not essential in dressing a grinding wheel such as that shown in Figure 8, it is preferred, though it will be understood that any other suitable procedure may be followed if desired. Preferably the grinding wheel is given a preliminary dressing in the manner stated, and is thereafter given a final dressing to assure precision. In the final dressing the diamond point or other cutting element should move in the same direction throughout the dressing operation, in order to avoid any inaccuracy due to slight wear of the shaft 55 and associated parts. In Figure 8 I have illustrated the final dressing ope eration, assuming that the cutting tool advances along the fiat surface H4 in the direction indicated by the arrow c, then moves about the arcuate surface H3 about axis a as indicated by the arrow 7, after which the cutting tool travels upward along the surface H5, as indicated by the arrow g.

In Figure 9 I have illustrated the dressing tool of my invention as used for dressing a concaved surface it on a grinding wheel l H. In this case the tip of the diamond point i3 is disposed above the axis a of shaft 23 a distance corresponding to the radius of the desired surface I [-6. In dressing this surface the posts 55 are disposed to limit swinging movement of lever 29 in either direction, as before, and by swinging the lever in clockwise direction, as viewed in Figure 2, from its extreme position in counterclockwise direce tion, the cutting tool is moved in the direction indicated by the arrow h, about the axis a, and the diamond point its dresses the surface H6 accurately to the desired arcuate curvature.

I have, for simplicity of description, illustrated the dressing tool of my invention as used, in Figures 8 and 9, for dressing grinding wheels having symmetrical profiles, and each having but one curved surface. It will be understood, however, that by disposing the dressing tool in proper relation to the grinding wheel and proper adjustment of the dressing tool, grinding wheels of a large variety of profileseither symmetric or asymmetric, and having one or more curved surfaces, either concaved or convexed--may be accurately dressed by the tool of my invention. In Figures 10 to 12, inclusive, I have shown fragmentarily several grinding wheels of different profiles which have been dressed by the tool of my invention, and it will be understood that various other profiles may also be dressed by that tool. The slot 5! is of materially greater extent than 180, as above noted. That is advantageous as enabling the dressing of clearances on the sides of a grinding wheel, by turning the lever 29 in either direction from its centered or zero position through an angle of more than 90, into proper position for dressing the desired clearance surface.

It will be understood, as above indicated, that changes in construction and arrangement of parts of the dressing tool of my invention may be resorted to without departing from the field and scope of such invention, and I intend to include all such variations, as fall within the scope of the appended claims, in this application in which the 10 preferred form only of my invention has been disclosed.

Iclaim:

, 1. In a tool of the character described, a frame comprising a base and an upright support, a shaft mounted through said support for oscillatory movement about a fixed axis, an operating lever fixed to said shaft at the outer face of said support, a block fixed to the inner end of said shaft, acarriage slidable on said block for rectilinear movement transversely of said shaft and restrained against relative turning movement, a tool arm fixed to said carriage extending inward therefrom, means for moving said carriage in either directionon said block, means for locking said carriage to said block in predetermined relatlon thereto, and means carried by said lever for looking it to said support in desired adjustment about said axis.

2. In a tool of the character described, a frame comprising a base andan upright support, a shaft mounted through said support for oscillatory movement about a fixed axis, an operating lever fixed to said shaft at the outer face of said support, a block fixed to the inner endof said shaft, a carriage slidable on said block for rectilinear movement transversely of said shaft and restrained against relative turning movement, a tool arm fixedto said carriage extending inward therefrom, releasable means for automatically locking said carriage to said block at a predetermined position thereon, means for moving said carriage in either direction on said block beyond said position and locking it to said block throughout such movement, and means for locking said lever to said support in desired adjustment about said axis.

3. In a tool of the character described, a frame comprising a base and an upright support, a shaft mounted through said support for oscillatory movement about a fixed axis, an operating lever fixed to said shaft at the outer face of said support, a block fixed to the inner end of said shaft, a carriage slidable on said block for rectilinear movement transversely of said shaft and restrained against relative turning movement, a tool arm fixed to said carriage extending inward therefrom having a tool receiving opening disposed with its axis intersecting said fixed axis, spring latch means for locking said carriage to said block in position with the axis of said opening in the vertical plane of said fixed axis, means for moving said carriage in either direction on said block beyond said position and looking it to said block during such movement, and means for locking saidlever to said support in desired ad .l'ustment about said axis.

4. In a tool of the character described, a frame comprising a base and an upright support, a shaft mounted through said support for oscillatory movement about a fixed axis, an operating lever fixed to said shaft at the outer face of said support, a substantially rectangular block fixed 'to the inner end of said shaft having at its inner face an inwardly projecting eye, a carriage slidable on said block for rectilinear movement transversely of said shaft and restrained against relative turning movement, a tool arm fixed to said carriage extending inward therefrom, said carriage having in its inner face a lengthwise channel receiving said eye, and a screw shaft in said channel threading through the eye rotatably mounted at its ends in said carriage and restrained against relative endwise movement.

5. In a tool of the character described, a frame comprising a base and an upright support, a shaft mounted through said support for oscillatory movement about a fixed axis, an operating lever fixed to said shaft at the outer face of said support, a block fixed to the inner end of said shaft, a carriage slidable on said block for rectilinear movement transversely of said shaft and re.- strained against relative turning movement, a tool arm fixed to said carriage extending inward therefrom having a tool receivingopening disposed with its axis intersecting said fixed axis, means for moving said carriage in either direction on said block and looking it thereto during such movement, and means for locking said lever to said support in desired adjustment about said axis.

6. In a tool of'th character described, a frame comprising a base and an upright support, a shaft mounted through said support for oscillatory movement about a fixed axis,'an'operating lever fixed to said shaft at the outer face of said support, a block fixed'to the inner endof said shaft, a carriage slidable on said block for rectilinear movement transversely of said shaft and restrained against relative turning movement, a tool arm fixed to said carriage extending inward therefrom having a tool receiving opening disposed with its axis intersecting s'ad fixed axis, means for moving said carriage in either direction on said block and looking it thereto during such movement, means carried by said lever for looking it to said'support'in desired-adjustment about said axis, and adjustable stops on said support at opposite sides of said lever for limiting turning movement thereof in either direction.

'7. In a tool of the character described, a'frame comprising a base and an upright support, a shaft mounted through said support for oscillatory movement about a fixed axis, the upper portion of said support being concentric with said axis'and having thereon a scale to indicate the extent of turning of said shaft in either direction, an operating lever fixed to said shaft at the outer face of said support carrying an index element cooperating with said scale, a "block fixed to the inner end of said shaft, a carriageslidable onsaid block for rectilinear movement transversely of said shaft and restrained against relative turning movement, a tool arm-fixed to said carriage extending inward therefrom-means for moving said carriage in either direction on said block and looking it thereto, during suchmovement, and means for locking said lever tosaid support in desired adjustment about said axis.

8. In a tool of the character described, a frame comprising a base and an upright support, a

shaft mounted through said support for oscillator movement abouta fixed axis, an operating lever fixed to said shaft at the outer face of said support, a block fixed to the'inn'er end of'jsaid shaft, a carriage slidable on said block for rectilinear movement transversely of said'shaft and restrained against relative turning movement, a tool arm fixed to said carriage'extending inward therefrom, means for moving said carriage in either direction on said blockand locking'it thereto during such movement, means for looking said lever to said support in desired adjust,- ment about said axis, and stops on said support at opposite sides of said lever adjustable concentrically with said axis and projecting outwardly of said support for limiting turning movement of said lever in either direction.

9. In a tool of the character described, a frame comprising a base and an upright support, a shaft mounted through saidsupport foroscillatory movement about a fixed axis, an operating lever fixed to said shaft at the outer face of said support, a block fixed to the inner end of said shaft, a, carriage slidable on said block for rectilinear movement transversely of said shaft and restrained against relative turning movement, a tool arm fixed to said carriage extending inward therefrom, means for moving said carriage in either direction on said block and looking it thereto during such movement, means for locking said lever to said support in desired adjustment about said axis, said support having therein a, slot concentric with said axis, and stops adjustable in said slot at opposite sides of said lever disposed for contact thereby for limiting turning thereof in either direction.

10. In a tool of the character described, a frame comprising a base and an upright support, a shaft mounted through said support for oscillatory movement about a fixed axis, a block fixed to the inner end of said shaft, an inwardly projecting eye carried by said block, a carriage slidable on said block for rectilinear movement transversely of said shaft having in its inner face a lengthwise channel receiving said eye, a tool arm fixed to said carriage extending inward therefrom, and a screw shaft in said channel threading through said eye rotatably mounted in said carriage and restrained against relative endwise movement.

11. Ina tool of the character described, a frame comprising a, base and an upright support, a shaft mounted through said support for oscillatory movement about a fixed axis, a block fixed to the inner end of said shaft, an inwardly projecting threaded member carried by said block, a carriage slidable on said block for rectilinear movement transversely of said shaft having in its inner face a lengthwise channel receiving said member, a tool arm extending inward from said carriage, and a screw shaft in said channel having threaded engagement with said member rotatably mounted in said carriage and restrained against relative endwise movement.

FRED M. BLEY,

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,596,701 Williams Aug. 17, 1926 v 2,336,758 Statia Dec. 14, 1943 2,377,934 Greig June 12, 1945 

